Image forming apparatus having a chassis containing a curved part that supports a roller bearing

Abstract

The image forming apparatus includes a chassis, a feed roller, and a press roller. The chassis includes first and side surfaces, a bottom surface that connects the first and second side surfaces, and a curved part formed unitarily with the bottom surface. The curved part has a feed roller bearing support portion. The feed roller is rotatably supported between the first and second side surfaces via feed roller support bearings for conveying paper. The feed roller bearing support portion of the curved part supports one of the feed roller support bearings. The press roller is rotatably supported between the first and second side surfaces for pressing on the feed roller. The feed roller has a paper conveying portion that has a plurality of projecting portions. A widthwise center of the paper conveying portion substantially matches with a widthwise center between the pair of feed roller bearings.

1. An image forming apparatus, comprising:
 a chassis with a first side surface, a second side surface, a bottom surface that connects the first and second side surfaces, and a curved part formed unitarily with the bottom surface, the curved part having a feed roller bearing support portion; 
 a print head supported by the chassis; 
 a feed roller rotatably supported between the first and second side surfaces via a pair of feed roller support bearings for conveying paper, one of the feed roller support bearings being supported by the first side surface and the feed roller bearing support portion of the curved part; 
 and a press roller rotatably supported between the first and second side surfaces for pressing on the feed roller with a predetermined amount of pressure, 
 the feed roller having a paper conveying portion with a plurality of projecting portions, 
 a widthwise center & the paper conveying portion substantially matching with a widthwise center between the pair of feed roller support bearings. 
 
     
     
       2. The image forming apparatus according to  claim 1 , further comprising
 a pair of press roller bearings for rotatably supporting both ends of the press roller; and 
 a pair of press arms for pressing the press roller against the feed roller with a predetermined amount of pressure, each of the pair of press roller bearings being mounted on each of the press arms, 
 the curved part further having a press arm support portion for rotatably supporting one of the press arms, and 
 the widthwise center of the paper conveying portion substantially matching with a widthwise center between the pair of press roller bearings. 
 
     
     
       3. The image forming apparatus according to  claim 1 , wherein
 a concave-shaped part is formed in the feed roller bearing support portion of the curved part on a side away from the press roller so as to bear the pressure from the press roller on the feed roller. 
 
     
     
       4. The image forming apparatus according to  claim 1 , wherein
 the feed roller has the paper conveying portion. 
 
     
     
       5. The image forming apparatus according to  claim 1 , wherein
 the chassis is made of metal. 
 
     
     
       6. An image forming apparatus comprising:
 a chassis with a first side surface, a second side surface, a bottom surface that connects the first and second side surfaces, and a curved part formed unitarily with the bottom surface, the curved part having a feed roller bearing support portion; 
 a feed roller rotatably supported between the first and second side surfaces via a pair of feed roller support bearings for conveying paper, one of the feed roller support bearings being supported by the feed roller bearing support portion of the curved part; 
 a press roller rotatably supported between the first and second side surfaces for pressing on the feed roller with a predetermined amount of pressure; 
 a print head pivotably supported between the first and second side surfaces; 
 a platen roller rotatably supported between the first and second side surfaces opposite the print head via a pair of platen roller bearings; and 
 a first side plate mounted on one of the first and second side surfaces of the chassis, the first side plate being unitarily formed with one of the feed roller bearings and one of the platen roller bearings, 
 the feed roller or the press roller having a paper conveying portion that has a plurality of projecting portions, 
 a widthwise center of the paper conveying portion substantially matching with a widthwise center between the pair of feed roller bearings, and 
 the curved part further having a platen roller bearing support portion for supporting one of the platen roller bearings. 
 
     
     
       7. The image forming apparatus according to  claim 6 , further comprising
 a second side plate mounted on the other of the first and second side surfaces of the chassis, the second side plate being unitarily formed with the other of the feed roller bearings and the other of the platen roller bearings. 
 
     
     
       8. An image forming apparatus, comprising:
 a metal chassis with a first side surface, a second side surface, a bottom surface that connects the first and second side surfaces, and a curved part formed unitarily with the bottom surface, the curved part having a feed roller bearing support portion, a press arm support portion, and a platen roller bearing support portion; 
 a feed roller rotatably supported between the first and second side surfaces via feed roller support bearings for conveying paper, one of the feed roller support bearings being supported by the feed roller bearing support portion of the curved part; 
 a press roller rotatably supported between the curved part and the second side surfaces via a pair of press roller bearings for pressing on the feed roller with a predetermined amount of pressure, the pair of press roller bearings rotatably supporting both ends of the press roller; 
 first and second side plates mounted on the first and second side surfaces of the chassis, the first and side plates being unitarily formed with the feed roller bearings and the platen roller bearings, 
 a print head pivotably supported between the curved portion and the second side surface; 
 a platen roller rotatably supported between the curved portion and the second side surface opposite the print head via a pair of platen roller bearings, one of the pair of platen roller bearings being supported by the platen roller bearing support portion of the curved portion; and 
 a pair of press arms for pressing the press roller against the feed roller with a predetermined amount of pressure, each of the pair of press roller bearings being mounted on each of the press arms, one of the press arms being supported by the press arm support portion of the curved portion, 
 wherein 
 the feed roller has a paper conveying portion that has a plurality of projecting portions, 
 a widthwise center of the paper conveying portion substantially matches with a widthwise center between the pair of feed roller bearing and a widthwise center between the pair of press roller bearings, and 
 a concave-shaped part is formed in the feed roller bearing support portion of the curved part on a side away from the press roller so as to bear the pressure from the press roller on the feed roller.